Collimation fustration!!!

[wookie1965]

Looks like your secondary just needs turning a bit so it shows a full circle its a tad off thats why you cannot see third mirror clip. Its not far off though it is very nearly there.

[NIGHTBOY]

Ahh I think I see what you mean now, the primary is misaligned.....

You should see 3 small black wotsits as you can only see two here...

[wookie1965]

Not the Primary the secondary the little mirror at the front turn that a tad or use the collimating screws to turn it to get it show a full circle.

[Carl Reade]

The small secondary mirror it should look like a round circle. The black shadow shape around it wont and shouldnt be circular it will appear off. As long as the small mirror is nice and round you should then see the three clips on the primary.

Carl

[NIGHTBOY]

Yes I've done that but now my first black circle is off centre...

[NIGHTBOY]

[Carl Reade]

Thats it have you noticed your third clip is now in view? That looks good to me.

Carl

[Carl Reade]

Thats it have you noticed your third clip is now in view? That looks good to me.

Carl

[wookie1965]

Yes that looks 100% better nice round circle, now just check your primary little black dot in centre of doughnut and your done looks fine .

[NIGHTBOY]

Right done that. They don't line up with the crosshairs in the collimation tube tho???

[wookie1965]

Your primary needs adjusting now get the black dot right in the centre of the doughnut the very small circle you can see through the focuser you will see it lining up as you turn the screws at the back of your scope.

[NIGHTBOY]

Yes I've already done it? The tiny black dot is in the middle of the white circle but they're not lining up with the crosshairs in the collimating tube????

[Carl Reade]

The primary mirror (the main mirror at the bottom) you need to adjust the three screws.  Loosen the locking nuts then adjust it until the cross hair is central. Dont touch the secondary as it looks fine (the small one).

Carl

[NIGHTBOY]

Ahh I see, so, the primary mirror will move the tiny centre dot, the white outer and the black outer. I thought it only moved the tiny centre dot. Sorry nooooob alert!

[wookie1965]

Set your scope u like you did before then leave the small mirror alone dont touch it at all you will never have to touch that again as long as you dont bump your scope. After you have done that use the 3 screws at the back of your scope where the big mirror is and move the little black dot into the small circle it will then line up.

[NIGHTBOY]

Yes the problem is tho..

If I set it so the focuser circle is central in the crosshairs, you can only see 2 clips on the primary.

[NIGHTBOY]

Can you just clarify...

Adjusting the primary mirror will only move the tiny central dohgnut dot???

[NIGHTBOY]

If the centre screw in the secondary mirror moves the focuser circle (small black outer circle) in to the centre of the crosshairs and the 3 Allen bolts line the secondary mirror up with the primary mirror then I have a problem.

If I set the focuser circle bang in the middle of the crosshairs, as soon an I turn the Allen bolts to get a full view of the primary, the focuser circle goes off centre of the crosshairs.

[wookie1965]

the centre screw moves your secondary in and out of your tube with a little bit of movement (Twisting) this needs to be centralised under the focuser forget everything else, once you have accomplished this with the 3 collimation screws you should see the 3 clips holding your primary mirror it doesnt matter about the dot or vanes at this point. Then all you need to do is use the 3 screws at the back of the scope on the primary to line up the dot in the little circle. Read through the last link i sent you he shows you a great way of blocking all the other stuff off so you are only looking at your secondary to get it in the right position.

[NIGHTBOY]

Ok wookie thanks. I'm am at work at the mo but I will read up when I get home.

If you could look at the last picture I posted and tell me what is wrong with it I would be most gratefull. I can see all 3 clips that hold the primary mirror and all the circles line up but they're not central with the crosshairs.

[NIGHTBOY]

What's happening is...

I use the screw to centralise the focuser. Then when I adjust the Allen bolts to get the 3 clips in view the focuser goes off centre.

[wookie1965]

Its a bit fiddly but read that post it makes things easier i was pulling my hair out the first time, now i don`t have to touch that part of the scope just tweak the back 3 screws and that`s all you will have to do, if you really cannot do it take it down to one of those astro society`s i posted to you there will be someone there that will help you.If i was closer i would have come and helped you no problem. The last picture looked perfect all you had to do was adjust your primary mirror the one at the back this would have brought the cross hairs and dot in the middle.

[NIGHTBOY]

I know what your saying, I need to get the focuser circle central with the crosshairs, then adjust the 3 bolts to bring the 3 clips of the primary mirror into view, it's just that when I'm adjusting the 3 bolts the focuser circle moves!! Haha nightmare.

[NIGHTBOY]

Th only thing that happens when I adjust the primary is the little dohgnut moves around, it has no effect in the small circles outside of that.

[wookie1965]

I know what your saying, I need to get the focuser circle central with the crosshairs, then adjust the 3 bolts to bring the 3 clips of the primary mirror into view, it's just that when I'm adjusting the 3 bolts the focuser circle moves!! Haha nightmare.

No No the clips will be seen from the first part of the collimation the crosshairs is the last part, the clips will be seen from when you adjust the secondary (little mirror)It will become so much clearer when you read that third link keep going through the pages their is only 3 but he puts coloured paper in (which you should) and blocks off the reflection of the primary when you take this out and adjust tilt you will see 3 clips then leave secondary alone. All you have to do then is primary and that is the easy bit, the website explains it all its got pictures so you can see what you are supposed to be seeing each step of the way.